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arch: aarch64: do EL2 init in EL3 if necessary

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If EL2 is implemented but we're skipping EL2, we should still
do EL2 init. Otherwise we end up with a bunch of things still
at their (unknown) reset values.

This in particular causes problems when different
cores have different virtual timer offsets.

Signed-off-by: James Harris <james.harris@intel.com>
This commit is contained in:
James Harris 2021-03-08 12:00:28 -08:00 • committed by Anas Nashif
commit 4e1926d508
1 changed files with 44 additions and 7 deletions
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51
arch/arm/core/aarch64/reset.c
View file

@ -7,6 +7,8 @@
#include <kernel_internal.h>
#include "vector_table.h"
void z_arm64_el2_init(void);
void __weak z_arm64_el_highest_plat_init(void)
{
/* do nothing */
@ -36,6 +38,28 @@ void z_arm64_el_highest_init(void)
isb();
}
enum el3_next_el {
EL3_TO_EL2,
EL3_TO_EL1_NO_EL2,
EL3_TO_EL1_SKIP_EL2
};
static inline enum el3_next_el el3_get_next_el(void)
{
if (!is_el_implemented(2)) {
return EL3_TO_EL1_NO_EL2;
} else if (is_in_secure_state() && !is_el2_sec_supported()) {
/*
* Is considered an illegal return "[..] a return to EL2 when EL3 is
* implemented and the value of the SCR_EL3.NS bit is 0 if
* ARMv8.4-SecEL2 is not implemented" (D1.11.2 from ARM DDI 0487E.a)
*/
return EL3_TO_EL1_SKIP_EL2;
} else {
return EL3_TO_EL2;
}
}
void z_arm64_el3_init(void)
{
uint64_t reg;
@ -64,6 +88,14 @@ void z_arm64_el3_init(void)
z_arm64_el3_plat_init();
isb();
if (el3_get_next_el() == EL3_TO_EL1_SKIP_EL2) {
/*
* handle EL2 init in EL3, as it still needs to be done,
* but we are going to be skipping EL2.
*/
z_arm64_el2_init();
}
}
void z_arm64_el2_init(void)
@ -89,6 +121,10 @@ void z_arm64_el2_init(void)
zero_cntvoff_el2(); /* Set 64-bit virtual timer offset to 0 */
zero_cnthctl_el2();
zero_cnthp_ctl_el2();
/*
* Enable this if/when we use the hypervisor timer.
* write_cnthp_cval_el2(~(uint64_t)0);
*/
z_arm64_el2_plat_init();
@ -114,6 +150,13 @@ void z_arm64_el1_init(void)
SCTLR_SA_BIT); /* Enable SP alignment check */
write_sctlr_el1(reg);
write_cntv_cval_el0(~(uint64_t)0);
/*
* Enable these if/when we use the corresponding timers.
* write_cntp_cval_el0(~(uint64_t)0);
* write_cntps_cval_el1(~(uint64_t)0);
*/
z_arm64_el1_plat_init();
isb();
@ -128,13 +171,7 @@ void z_arm64_el3_get_next_el(uint64_t switch_addr)
/* Mask the DAIF */
spsr = SPSR_DAIF_MASK;
/*
* Is considered an illegal return "[..] a return to EL2 when EL3 is
* implemented and the value of the SCR_EL3.NS bit is 0 if
* ARMv8.4-SecEL2 is not implemented" (D1.11.2 from ARM DDI 0487E.a)
*/
if (is_el_implemented(2) &&
((is_in_secure_state() && is_el2_sec_supported()) || !is_in_secure_state())) {
if (el3_get_next_el() == EL3_TO_EL2) {
/* Dropping into EL2 */
spsr |= SPSR_MODE_EL2T;
} else {